#ACE2-like enzymatic activity in #COVID19 #convalescents with persistent pulmonary symptoms associated with #immunoglobulin

ABSTRACT

Many difficult-to-understand clinical features characterize COVID-19 and post-acute sequelae of COVID-19 (PASC or long COVID [LC]). These can include blood pressure instability, hyperinflammation, coagulopathies, and neuropsychiatric complaints. The pathogenesis of these features remains unclear. The SARS-CoV-2 Spike protein receptor-binding domain (RBD) binds angiotensin converting enzyme 2 (ACE2) on the surface of host cells to initiate infection. We hypothesized that some people convalescing from COVID-19 may produce anti-RBD antibodies that resemble ACE2 sufficiently to have ACE2-like catalytic activity, that is, they are ACE2-like proteolytic abzymes that may help mediate the pathogenesis of COVID-19 and LC. In previous work, we showed that some people with acute COVID-19 had immunoglobulin-associated ACE2-like proteolytic activity, suggesting that some people with COVID-19 indeed produced ACE2-like abzymes. However, it remained unknown whether ACE2-like abzymes were seen only in acute COVID-19 or whether ACE2-like abzymes could also be identified in people convalescing from COVID-19. Here, we show that some people convalescing from COVID-19 attending a clinic for people with persistent pulmonary symptoms also have ACE2-like abzymes and that the presence of ACE2-like catalytic activity correlates with alterations in blood pressure in an exercise test.

IMPORTANCE

Patients who have had COVID-19 can sometimes have troublesome symptoms, termed post-acute sequelae of COVID-19 (PASC) or long COVID (LC), which can include problems with blood pressure regulation, gastrointestinal problems, inflammation, blood clotting, and symptoms like “brain fog.” The proximate causes for these problems are not known, which makes these problems difficult to treat definitively. We previously found that some acute COVID-19 patients make antibodies against SARS-CoV-2, the virus that causes COVID-19, that act like an enzyme, angiotensin converting enzyme 2 (ACE2). ACE2 normally helps regulate blood pressure and serves as the receptor for SARS-CoV-2 in the body. We show that patients convalescing from COVID-19 also make antibodies that act like ACE2 and that the presence of those antibodies correlates with problems in blood pressure regulation. The findings provide a new opening to potentially understanding the causes of LC, and so provide direction for the development of new treatments.

Source: mBio, https://journals.asm.org/doi/full/10.1128/mbio.01735-25?af=R

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#Neuroinvasive #Oropouche virus in a patient with #HIV from extra-Amazonian #Brazil

{Excerpt} A novel reassortant Oropouche virus (OROV) lineage (with medium [M], large [L], and small [S] RNA segments : M1L2S2) has driven Brazil's largest and most geographically widespread OROV epidemic , expanding beyond the endemic Amazon basin to establish local transmission across multiple Brazilian states and other previously unaffected Latin American countries . The rapid spread of this lineage underscores its evolutionary potential and reinforces its significance as a public health threat .1 Similar to chikungunya and Zika viruses, expanding arboviruses can exhibit unexpected clinical and epidemiological shifts , including vertical transmissions , neuroinvasive effects, and potentially fatal outcomes.2–4 Although OROV typically causes self-limited febrile illness, accumulating clinical and experimental evidence suggests neurotropic potential .5 This Correspondence describes the first confirmed case of neuroinvasive OROV infection caused by the emergent M1L2S2 lineage in ext...

Stability of #influenza viruses in the #milk of #cows and #sheep

Abstract In late 2023, H5N1 high pathogenicity avian influenza (HPAIV) started circulating in dairy cattle in the USA . High viral titres were detected in milk from infected cows , raising concerns about onwards human infections . Although pasteurisation was shown to effectively inactivate influenza viruses in milk, unpasteurised milk still poses a risk of infection, both from occupational exposure in dairies and from the consumption of raw milk. We therefore assessed how long influenza viruses could remain infectious for in milk without heat inactivation. We examined the stability of a panel of influenza viruses in milk , including a contemporary H5N1 HPAIV and a variety of other influenza A and D viruses. We incubated viruses in cows' milk under laboratory conditions : at room temperature to simulate exposure in dairies and at 4°C to simulate exposure to refrigerated raw milk. Following an isolated report of H5N1 viral RNA being detected in milk from a sheep in the UK , we also c...

#Evidence of #Viremia in Dairy #Cows Naturally Infected with #Influenza A {#H5N1} Virus, #California, #USA

Abstract We confirmed influenza A virus (IAV) by PCR in serum from 18 cows on 3 affected dairy farms in California, USA . Our findings indicate the presence of viremia and might help explain IAV transmission dynamics and shedding patterns in cows. An understanding of those dynamics could enable development of IAV mitigation strategies. Source: US Centers for Disease Control and Prevention, https://wwwnc.cdc.gov/eid/article/31/7/25-0134_article ____

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